Radial counterflow steam stripper

Abstract

Turbine exhaust steam, axially fed between counter-rotating radial flow disk turbines, separates into: (1) a radially inward flow of low enthalpy dry steam, and (2) a radially outward flow of high enthalpy steam, noncondensibles, and condensate. The radially inward flow goes to a conventional condenser. The radially outward flow loses enthalpy turning the disk turbines as it passes in the boundary layers against the disks, thus becoming low enthalpy dry steam, and the counter-rotation of the disks by impinging mass flow of condensate, high enthalpy steam, and noncondensibles sustains a cascade of dynamic vortex tubes in the shear layer between the boundary layers. The low enthalpy dry steam resulting from work being done flows into the condenser through the vortex cores of fractal turbulence. Condensate exits the periphery of the workspace, ready to be pumped back into the Rankine cycle. More condensate is recovered from the low enthalpy vapor in the condenser. Heat rejection from the cooling water circuit is easier because a significant mass fraction does not enter the condenser. Dynamic evaporative cooling of cooling water, uses fractal turbulence between counter-rotating centrifugal impellers, fed at their common axis of rotation with cooling water. Chilled water flows radially outward to recirculation, and hot water and vapor flows radially inward to the impeller axis of rotation. Vapor is stripped through the vortex cores of fractal turbulence into a condenser where it condenses as distilled water. Ultimate heat rejection is into the environment without discharge of vapor.

Description

APPLICATION HISTORY[0001]Applicant claims priority based on U.S. Provisional Patent Application No. 61 / 041,110, filed Mar. 31, 2008, which is incorporated herein by reference.FIELD OF THE INVENTION[0002]This invention applies to exhaust steam handling means, to means for evaporative cooling, to vacuum distillation, and to means for energy and water conservation at power plants.BACKGROUND OF THE INVENTIONWater and Energy Waste at Thermal Power Plants[0003]The thermal efficiency of a modern steam power plant is only ˜35%. Most of the energy in its fuel is wasted. Inefficiency is principally due to heat rejection in the cooling tower, where waste heat from the steam turbine exhaust is dumped into the atmosphere as latent heat in vapor of cooling water.[0004]The vapor out of the cooling tower is wasted water as well as wasted energy. Fresh water used for thermal power plant cooling water is becoming a precious commodity, forcing a choice between water for power and water for people. The...

AI Technical Summary

Benefits of technology

[0025]The conventional approach is to dump both the high energy molecules and the low energy molecules into the condenser, along with the condensate and noncondensibles. The present invention strips out the low energy molecules and passes only those to the condenser, leaving the high energy molecules, condensate, and noncondensibles out of the condenser and doing useful work sustaining a radial counterflow forcing regime and even turning a generator.

[0026]The steam stripper works on the turbine exhaust energy which otherwise would be totally wasted up the cooling tower. A generator may be run by connecting a peripheral drive wheel between the disks, thereby increasing the efficiency of the power plant. By pushing the disks, the high enthalpy vapor loses enthalpy and condenses, thereby reducing the load on the condenser and allowing for a more intelligent system of cooling water cooling.

Problems solved by technology

Most of the energy in its fuel is wasted.

Inefficiency is principally due to heat rejection in the cooling tower, where waste heat from the steam turbine exhaust is dumped into the atmosphere as latent heat in vapor of cooling water.

The vapor out of the cooling tower is wasted water as well as wasted energy.

The amount of water wasted by conventional thermal power plants is enormous.

Vapor out of the cooling tower is wasted water.

The blow-down has a high percentage of total dissolved solids and is a water pollution problem as well as a waste of a precious resource.

The waste heat absorbed by the cooling water of the shell and tube surface condenser could be discharged immediately by dumping the cooling water into the environment (the once-through process), but this option is not favored because thermal pollution of the environment is usually not acceptable.

Air cooling is another option, but for large power plants it is not satisfactory because of the low heat flux between fins and ambient air, even when the air is blown.

When the heat load is large and the ambient air is hot, such as on a hot summer day when many air conditioners are running, air cooling may fail.

Typically 3-6% of cooling water sprayed in is lost by evaporation in the cooling tower, a large waste of water as well as energy.

A major siting constraint on nuclear plants is the scarcity of fresh water.

Of course, seawater or alkaline water won't work for a cooling water circuit because it contains scale-forming dissolved solids which precipitate at high temperatures and would quickly clog the tubes.

Petroleum refineries have very large cooling water systems.

A typical large refinery processing 40,000 metric tons of crude oil per day (˜300,000 barrels per day) circulates about 80,000 cubic meters of water per hour through its cooling tower system, evaporating and wasting a prodigious amount of precious fresh water.

Dumping vapor in the atmosphere is not a sustainable practice, and a need exists for an alternative method for heat rejection which does not waste water.

Infected steam billowing from cooling towers is a visible threat to the health of the community.

Cooling towers, whose profile is associated with the nuclear disaster at Three Mile Island, and which emit huge volumes of what looks like smoke, are not good for public relations.

They are a prominent and objectionable feature of any power plant.

Cascading of vortex tubes has the problem of reduced feed pressure at each successive stage of the cascade, with consequent loss of separation, unless there is some boosting of feed pressure between stages.

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